title: Endogenous opioids mediate basal hedonic tone independent of dopamine D-1 or D-2 receptor activation.
mesh_terms: D000339:Affect / Q000187:drug effects / Q000502:physiology; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects / Q000502:physiology; D003213:Conditioning, Psychological / Q000187:drug effects / Q000502:physiology; D005260:Female; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D018847:Opioid Peptides / Q000378:metabolism*; D017447:Receptors, Dopamine D1 / Q000235:genetics* / Q000378:metabolism*; D017448:Receptors, Dopamine D2 / Q000235:genetics* / Q000378:metabolism*
chemical_list: D009292:Narcotic Antagonists; D018847:Opioid Peptides; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D009270:Naloxone